The present invention relates to water-laden solid matter of inorganic oxide particles which are synthesized by vapor phase process (hereinafter referred to as xe2x80x9cvapor-phase processed inorganic oxide particlesxe2x80x9d), slurry for polishing which is manufactured from such water-laden solid matter and used for the manufacture of semiconductor devices such as VLSI, and manufacturing method for manufacturing semiconductor devices using the slurry. The water-laden solid matter according to the present invention is so high in bulk density as to be easy in storage, transport, etc. The slurry for polishing according to the present invention is so high in stability as to be free from problems such as increase in viscosity, gelation and separation and precipitation during storage.
Recently, slurry which is obtained by dispersing the vapor-phase processed inorganic oxide particles in the water has been used for polishing semiconductor devices such as VLSI. Here, the xe2x80x9cvapor-phase processed inorganic oxide particlesxe2x80x9d refers in case of silica, for example, to inorganic oxide particles which are synthesized by fumed process for synthesizing silica by allowing silicon tetrachloride to react with hydrogen and oxygen and then hydrolyzed (high-temperature flame hydrolysis process) or by vapor phase process such as Nano-phase Technology""s process for synthesizing inorganic oxides particles by heating a metal to a temperature above the melting point of such metal to produce metal steam and allowing such metal steam to react with oxygen (metal evaporation and oxidation process).
The vapor-phase processed inorganic oxide particles, which are raw materials of the slurry for polishing semiconductor devices, are so fine in particle size as to be low in bulk density. For example, the bulk density of silica synthesized by the fumed process is approx. 0.05 g/cm3, and the bulk density of alumina synthesized by the fumed process is approx. 0.05 g/cm3, and the bulk density of silica synthesized by the Nano-phase Technology""s process is approx. 0.05 g/cm3.
As described above, the vapor-phase processed inorganic oxide particles is so low in bulk density as to be bulky occupying a large space for storage and transport, hard to handle and high in cost. For this reason, it has been desired to increase the bulk density of the vapor-phase processed inorganic oxide particles.
For increasing the bulk density of the vapor-phase processed inorganic oxide particles, there is a method of releasing air from the vapor-phase processed inorganic oxide particles. However, this method can increase the bulk density only up to 0.2 g/cm3.
For this reason, it has been examined to store or transport the vapor-phase processed inorganic oxide particles in the state dispersed in water or any other liquid. However, there is a problem with this method that the aqueous dispersed matter of the vapor-phase processed inorganic oxide particles is unstable with extremely quick flocculation. For the stable storage of the aqueous dispersed matter of the vapor-phase processed inorganic oxide particles, it may be possible to adjust the pH of the aqueous dispersed matter or add some dispersant. However, if these methods are used, the aqueous dispersed matter of the vapor-phase processed inorganic oxide particles may be limited in use after the adjustment of the pH or the addition of some dispersant.
Equipment for manufacturing the slurry for polishing semiconductor devices may be installed within clean rooms or clean booths to avoid the mixture of dirt or the like. However, this cause a problem that the vapor-phase processed inorganic oxide particles, which are raw materials of the slurry for polishing, are so fine as to easily float in the air in the state of dust and lower the degree of cleanliness of the clean rooms or clean booths. To solve this problem, it has been desired to take measures so that the vapor-phase processed inorganic oxide particles cannot float in the air in the state of dust.
An object of the present invention is to increase the bulk density of the vapor-phase processed inorganic oxide particles, which are raw materials of the slurry for polishing, to make the vapor-phase processed inorganic oxide particles to be suitable to storage and transport. Another object of the present invention is to take measures so that the vapor-phase processed inorganic oxide particles cannot float in the air in the state of dust. Still another object of the present invention is to manufacture highly stable slurry for polishing semiconductor devices by using the vapor-phase processed inorganic oxide particles which are suitable to storage and transport and have been so arranged as not to float in the air in the state of dust. And still another object of the present invention is to provide manufacturing method for manufacturing semiconductor devices using the above slurry.
The inventors of the current invention earnestly examined these problems for solution, and as result, found that by adding a specific quantity of water thereto, the vapor-phase processed inorganic oxide particles could be increased in bulk density, could be stably stored for a long time, and could be substantially reduced in the production of dust, which led to the present invention.
The water-laden solid matter according to the present invention is characterized by being obtained by adding 40 to 300 weight parts of the water to 100 weight parts of the inorganic oxide particles synthesized by vapor phase process.
The water-laden solid matter according to the present invention is water-laden solid matter which is characterized by being obtained by adding 40 to 300 weight parts of the water to 100 weight parts of the inorganic oxide particles synthesized by either the fumed process (high-temperature flame hydrolysis process) or the Nano-phase Technology""s process (metal evaporation and oxidation process).
The water-laden solid matter according to the present invention is characterized by being obtained by adding 40 to 300 weight parts of the water to 100 weight parts of the inorganic oxide particles synthesized by either the fumed process or the vapor phase process such as the Nano-phase Technology""s process and granular matter within a range of 0.3 to 3 g/cm3 in bulk density and within a range of 0.5 to 100 mmxcfx86 in average particle size. Here, and hereinafter, xcfx86 denotes average particle size diameter.
Also, the slurry for polishing according to the present invention is characterized by being obtained by dispersing the water-laden solid matter prescribed by any of the above methods in the water so that the average size of the dispersed particles can be within a range of 0.05 to 1.0 xcexcm.
Also, the manufacturing method according to the present invention is characterized by manufacturing semiconductor devices using the above slurry for polishing. Here, the semiconductor devices refers to, for example, polished wafers, various devices having or equipped with the above wafers, and various devices manufactured of the above wafers (in other words, various devices being mounted on the above wafers), and the like.